He was elected as the Member for Whitford in 1993 and, following a re-distribution of boundaries, was re-elected for the seat of Hillarys in 1996.[2]

He served in the Court government as Minister for Works; Services; Citizenship and Multicultural Interests from December 1999 until February 2001.[1]

Johnson became Minister for Police, Emergency Services and Road Safety with the return to power of the Coalition in September 2008.[3]

In his first two years as minister in the Barnett government, Johnson introduced 16 bills into the Legislative Assembly.[4] Many of them were controversial and high profile [5] including increasing the impounding period of a vehicle for anyone convicted of a hoon offence.[6] Other measures were to ensure motorists with a blood alcohol reading of 0.08 or above lost their licence immediately at the roadside,[7] that all revenue from speed and red light cameras would go to road safety projects[8] and a proposal for Australia's first online sex offender register.[9]

Investigations following two major bushfires fires with the loss of 71 homes in the Perth hills[10][11] and in the Margaret River area resulted in severe criticism and Johnson losing the Emergency Services portfolio.[12]

Before the findings of the inquiries in 2011, political commentator Peter Van Onselen named Johnson among Australia's 'Top ten politicians you could trust', writing that "he is real and what you see is what you get".[13] The following year Federal Liberal MP for Canning Don Randall attacked Johnson in the Federal Parliament, labelling him bumbling, weak and incompetent.[14] In turn, Johnson called for Randall to be sacked over misused expenses claims.[15]

He was removed from the Emergency Services Portfolio on 6 December 2011 and the Police and Road Safety portfolio on 29 June 2012 in a Cabinet reshuffle by Premier Colin Barnett.[3][16][17] At the 2013 Western Australian State Election, Johnson was re-elected to the seat of Hillarys.[18]